diff --git a/src/System.Management.Automation/engine/hostifaces/MshHost.cs b/src/System.Management.Automation/engine/hostifaces/MshHost.cs
index 64d8f1170f2..7ee89d14b12 100644
--- a/src/System.Management.Automation/engine/hostifaces/MshHost.cs
+++ b/src/System.Management.Automation/engine/hostifaces/MshHost.cs
@@ -290,6 +290,7 @@ public virtual bool DebuggerEnabled
     /// This interface needs to be implemented by PSHost objects that want to support the PushRunspace
     /// and PopRunspace functionality.
     /// </summary>
+#nullable enable
     public interface IHostSupportsInteractiveSession
     {
         /// <summary>
@@ -317,6 +318,6 @@ public interface IHostSupportsInteractiveSession
         /// Returns the current runspace associated with this host.
         /// </summary>
         [SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Runspace")]
-        Runspace Runspace { get; }
+        Runspace? Runspace { get; }
     }
 }